import sys
import io, os
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

n = int(input())
g = [[] for i in range(n)]
G = [[] for i in range(n)]
for i in range(n-1):
    a, b = map(int, input().split())
    a, b = a-1, b-1
    G[a].append(b)
    G[b].append(a)
    g[a].append(b)
    g[b].append(a)

if n == 2:
    print('Yes')
    exit()

from collections import deque
q = deque([])
leaf = []
for v in range(n):
    if len(g[v]) == 1:
        q.append(v)
        leaf.append(v)

if len(q) == 2:
    print('Yes')
    exit()

N = n
while N > 2:
    l = len(q)
    N -= l
    for i in range(l):
        v = q.popleft()
        for u in g[v]:
            g[u].remove(v)
            if len(g[u]) == 1:
                q.append(u)
#print(list(q))
if len(q) >= 2:
    print('No')
    exit()
s = q[0]
#print(s)
q = deque([])
q.append(s)
dist = [-1]*len(g)
dist[s] = 0
while q:
    v = q.popleft()
    for u in G[v]:
        if dist[u] == -1:
            dist[u] = dist[v]+1
            q.append(u)
D = set()
for l in leaf:
    D.add(dist[l])
if len(D) == 1:
    print('Yes')
else:
    print('No')